US 12,388,527 B2
Brillouin gain spectrum distribution measurement method and equipment
Tomokazu Oda, Musashino (JP); Daisuke Iida, Musashino (JP); Atsushi Nakamura, Musashino (JP); Yusuke Koshikiya, Musashino (JP); and Nazuki Honda, Musashino (JP)
Assigned to NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
Appl. No. 18/272,188
Filed by NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
PCT Filed Jan. 26, 2021, PCT No. PCT/JP2021/002547
§ 371(c)(1), (2) Date Jul. 13, 2023,
PCT Pub. No. WO2022/162718, PCT Pub. Date Aug. 4, 2022.
Prior Publication US 2024/0146413 A1, May 2, 2024
Int. Cl. H04B 10/2537 (2013.01); G01D 5/353 (2006.01)
CPC H04B 10/2537 (2013.01) [G01D 5/35364 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A Brillouin gain spectrum distribution measuring method comprising:
making probe light of continuous light and pump light of continuous light incident from one end and the other end of an optical fiber under test, respectively, to generate a Brillouin action in an entire section of the optical fiber under test;
making pulse-like pulsed pump light having the same optical frequency as that of the pump light incident from the other end of the optical fiber under test in a state where the Brillouin action in the entire section is maintained;
measuring an intensity of the light output from the other end of the optical fiber under test;
for each optical frequency difference between the probe light and the pump light, extracting an amplification component of the probe light amplified by the pulsed pump light by subtracting an intensity component of the probe light and a component of the probe light amplified by the pump light from the measured intensity of the light, thereby obtaining a Brillouin gain spectrum in a distributed manner in a longitudinal direction of the optical fiber under test.